diff options
Diffstat (limited to 'mm/compaction.c')
| -rw-r--r-- | mm/compaction.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 6149a2d324be..0fb3b89b3967 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -229,6 +229,33 @@ static void reset_cached_positions(struct zone *zone) pageblock_start_pfn(zone_end_pfn(zone) - 1); } +#ifdef CONFIG_SPARSEMEM +/* + * If the PFN falls into an offline section, return the start PFN of the + * next online section. If the PFN falls into an online section or if + * there is no next online section, return 0. + */ +static unsigned long skip_offline_sections(unsigned long start_pfn) +{ + unsigned long start_nr = pfn_to_section_nr(start_pfn); + + if (online_section_nr(start_nr)) + return 0; + + while (++start_nr <= __highest_present_section_nr) { + if (online_section_nr(start_nr)) + return section_nr_to_pfn(start_nr); + } + + return 0; +} +#else +static unsigned long skip_offline_sections(unsigned long start_pfn) +{ + return 0; +} +#endif + /* * Compound pages of >= pageblock_order should consistently be skipped until * released. It is always pointless to compact pages of such order (if they are @@ -1955,8 +1982,14 @@ static isolate_migrate_t isolate_migratepages(struct compact_control *cc) page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn, cc->zone); - if (!page) + if (!page) { + unsigned long next_pfn; + + next_pfn = skip_offline_sections(block_start_pfn); + if (next_pfn) + block_end_pfn = min(next_pfn, cc->free_pfn); continue; + } /* * If isolation recently failed, do not retry. Only check the |